Stop motions for roving frames have long been known. See, for example, U.S. Pat. No. 3,363,285 to Foster. Foster discloses the use of a control rod 30 extending above a row of sensors or detector fingers, each of which is normally supported by a strand or end of sliver but which is movable upon the strand breaking or becoming slack to cause its associated contact finger to engage the control rod and complete a circuit to stop the machine. The Foster apparatus is mounted on a creel arm which is stationary and over which the sliver is drawn in its path from the supply cans to the drafting rolls. The use of the Foster stop motion on a stationary guide in the form of a creel has proven objectionable in the processing of sliver with little tensile strength. Such sliver tends to break easily when subjected to the friction imposed by being drawn over a stationary bar and beneath the sensors.